Various colored contact lenses are known in the art. One class of colored lenses includes "cosmetic" lenses useful for enhancing or changing the apparent color of the wearer's iris. Generally, these lenses include a colored iris section, and the colored contact lenses may include an optical correction, for example to accommodate farsightedness or nearsightedness of the wearer of the contact lens, or the contact lenses may be provided with the colored iris section solely for cosmetic purposes. Examples of such contact lenses are disclosed in U..S Pat. Nos. 5,120,121 and 4,582,402. The colored contact lenses of U.S. Pat. No. 4,582,402 are produced by printing a colored, opaque, intermittent pattern over the iris section of a contact lens. The colored contact lenses of U.S. Pat. No. 5,120,121 are produced by applying a pattern comprised of lens forming mixture doped with a tint to a mold surface, subjecting the mold to polymerization conditions so as to partially or fully polymerize the pattern on the mold surface, dispensing a conventional lens forming monomer mixture which does not contain ink into the mold such that it submerges the previously polymerized pattern, and polymerizing this mixture to obtain a contact lens.
In addition to the cosmetic contact lenses, U.S. Pat. Nos. 4,576,453 and 4,707,236 disclose a contact lens for light sensitive lens wearers having a progressively optically graded area therein. In U.S. Pat. No. 4,707,236, such lenses are made by bringing an ionized dye into contact with the lens gel material at a central point, and applying an electric potential across the lens gel, thus causing the dye to migrate towards the periphery, and whereby the higher concentration of dye is at the central point with the concentration progressively diminishing towards the periphery.